P196 Risk of venous thromboembolism according to disease activity, hospitalisation, or surgry in inflammatory bowel disease: a nationwide cohort study

Abstract

Background: The risk of venous thromboembolism (VTE) of inflammatory bowel disease (IBD) patients is higher than general population. Guidelines recommend primary prophylaxis of venous thromboembolism during their certain periods, yet little known about the magnitude of their different periods. We estimated the risk of VTE during a hospitalised flare, a non-hospitalised flare, a hospitalisation without flare, IBD-related surgery, and other major surgery. Method(s): Using the National Health Insurance claims data for the entire Korean population, we conducted cohort study, including 33 131 patients with IBD and 198 825 age- and sex-matched controls, from January 2014 until December 2016. Result(s): Of 33 131 patients with IBD and 198 825 matched controls, 110 patients and 376 controls developed VTE. The overall VTE risk was higher in patients with IBD [adjusted hazard ratio (aHR) 2.10; 95% confidence interval (CI) 1.70-2.61], compared with controls. The risk of VTE during a non-hospitalised flare of IBD patients was higher compared with controls (aHR, 2.86; 95% CI, 1.70-4.80). The risks of VTE were increased much more during a hospitalisation with non-flare (aHR, 12.97; 95% CI, 8.68-19.39) and a hospitalised flare (aHR, 19.36; 95% CI, 9.59-39.07). The risk of VTE was highest at the time of IBD-related surgery (aHR, 40.81; 95% CI, 10.16-163.92). Also, the risk at the time of other major surgery was increased (aHR, 15.44; 95% CI, 7.65-31.12). Heat map of risk of venous thromboembolism by different period of IBD patients. The colour intensity of the heat map is based on the hazard ratios for venous thromboembolic event Conclusion(s): The prophylaxis of VTE for Asian patients with IBD should be considered at the time of a hospitalised flare and IBDrelated surgery. However, the prevention of VTE is not needed for non-hospitalised patients with flare.